curl -s -X GET http://localhost:8080/pdb/query/v4/facts   --data-urlencode query@test --data-urlencode 'pretty=true'

curl -X POST http://localhost:8080/pdb/query/v4/facts \
  -H 'Content-Type:application/json' \
  -d '{"query":["and",["=","certname","FQDN"],["=","name","ipaddress"]]}'

content of file test :

["and",["=","certname","FQDN"],["or",["=","name","ipaddress"]]]

["and",["=","certname","FQDN"],["=","name","ipaddress"]]

["and",
  ["=", "name", "bios_version"],
  ["in", "certname",
    ["extract", "certname", ["select_facts",
                              ["and",
                                ["=", ["fact", "manufacturer"], "Dell Inc."],
                                ["=", ["fact", "productname"], "PowerEdge R620"]]]]]]
                                
To select all DELL model
["and",
  ["=", "name", "bios_version"],
  ["in", "certname",
    ["extract", "certname", ["select_facts", ["=", ["fact", "manufacturer"], "Dell Inc."] ]]]]
    
To get hostname in fact : 
["and",
  ["=", "name", "hostname"],
  ["in", "certname",
    ["extract", "certname", ["select_facts", ["=", ["fact", "hostname"], "myhostname"] ]]]]
    
Request 2 facts : 
[ "or",
    ["=", "name", "ipaddress"],
    ["=", "name", "operatingsystem"]
  ]
  
Query with mutliple fact with OR :
["and",
  ["=", "name", "hostname"],
  ["in", "certname",
    ["extract", "certname", ["select_facts",
                              ["or",
                                ["=", ["fact", "s_role"], "role1"],
                                ["=", ["fact", "s_role"], "role2"],
                                ["=", ["fact", "s_role"], "role3"]]]]]]
                                

Query with mutliple fact with OR and AND:
["and",
  ["=", "name", "hostname"],
  ["in", "certname",
    ["extract", "certname", ["select_facts",
                              ["and",
                                ["=", ["fact", "s_datacenter"], "mydc"],
                                ["or",
                                  ["=", ["fact", "s_role"], "role1"],
                                  ["=", ["fact", "s_role"], "role2"],
                                  ["=", ["fact", "s_role"], "role3"]]]]]]]